Process of recovering the nickel contained in basic nickel precipitates.



PATENTED JUNE 25 H. H. DOW, W. S. GATES & A. E. SCHAEFBR. PROCESC OP RECOVERING THE NICKEL CONTAINED IN BASIC NICKEL PRECIPITATES.

APPLICATION FILED APR. 18. 1906.

:fll d zedby'the -ha'logento black nickelic 'hy-r .Rdlate, which latter lr'emains insoluble unless To all whom it may concern:

UNITED sTATEs PATENT oEErcE.

HERBERT H. now AND WALTER 'seATEs, OF MIDLAND, MICHIGAN, f

AND ARTHUR E. scHAEFER, ORA-CLEVELAND, omo, ASSIGNORS,'

BY MESNE ASSIGNMENTS, TO THE ONTARIO NICKEL COMPANY, LIM

' ITED, oF WpRTHINcToN, CANADA, A-GORP RATION E CANADA. 'rao'c'gsstr'nzcovtnme THE NICKEL CQNTAINEDYIN BASIC NICKEL P Ec lBITKTTES-Q five r iee f e tw efi e i Application filedlpril 18.1906. Serial in: aia'ci;

? r;tmua June 25,1907.

Be it known that we, HERBERT HQ Dow iand WALTER-gs. GA ES, of Midland, count of Midland, Y'Michigan, and A THUR SGHAEFER, ofOleveland, county of Cuyahoga, Ohio, citizens of the United States, have 1n-' vented a new and useful Im rovement in Processes of Recovering the N el Contained in- Basic Nickel Precipitates, of which the fol-' lowing is a specificatlon, the principle of the invention being herein explained, and "the best mode in which we have contemplated ap lying that principle, so as to distinguish om other lnventlons. Our invention relates to methods of ren- '.i, {derin soluble the nickel contained in basic l-gnicke precipitates when the latter are treated free halogens, jfOI instance, when nick- .T-flous hydrate or nickelous carbonate, as

'a5"-NiCO .NiO H,, or a mixture of the two is to be dissolved'and perhaps later electro'lyzed for metallic nickel.

Said invention consists of steps hereinafter fully described and specifically set forth in the claims. The annexed description sets forth in detail certain steps embodying the invention,

such disclosed steps constituting but one of various ways in which the principle of the invention may be used.

' An approved form of apparatus for carrying out the steps thus described is conventionally illustrated in the single figure of the annexed drawing.

It is well known that when basic nickel Brecipitates'such as the hydrate and the caronate, are treated with free halogens, such 'as chlorin and bromin, only a part of the ,nickel is dissolved to soluble haloids, and the balance remains insoluble, having been oxihydrate is a's'follows:

of the nickel has been rendere'd so uble. I The proportion of nickel which is rendered soluble varies accordin' to circumstances, but .the ratio of thesolu le nickel to 'the insoluble can never exceed the ratio of one to'two, bywhichj it will be noted that no more than one-third of the nickel can be dissolved with dilute halo ens, A given amount of chlorin which acts or a length of time great enough to give com lete action, would {produce 33% of solu le nickel We have found that the strength of the halogen has'noinfiuence on the above ratio-inso far as ultima'te'resultsare concerned, but a stron halo en will, of

course, act more rapidly. therefore, that in order to dissolve all of the t will beevident,

nickel by means of the halogen, it will be nec- 1 essary to have some reducing agent present which will revent the formationof nickelic hydrate. uch reducing agents which might be used are carbon compounds, such as 011s, etc., any of which would, however, introduce soluble carbon compounds into the solution, which would be undesirable for electrolytic purposes; but we have discovered that the element sulfur in some form, either alone, or in some sulfur-containing compound such as hydro en sulfid, sulfur dioxid or sulfur" chlori .the latter either SCI be used for this pur ose, the sulfur as element not only acting we mechanically but pos-' sessing an immense reducing power 1n a small bulk and small weight, and at a small exor 2 2 ay pense', having, for instance, three times'the reducm power of sulfurin the condition of sulfur 'oxid, as I The reaction when the basic nickel precipitate is treated with free halogen 1n the presence of sulfur, is. as follows:

4Nio,H s 301 SNiOl, Niso, 4H4),

by which it will be noted that 32 parts by weight of sulfur are sufficient to cause the complete solution of-235 parts by weight of nickel, or 371 arts by. weight of nickelous to hydrate (NiO IE tion quickly it is necessary to have the sulfur in a very fine state of subdivision, such as ground flowers of sulfur or brimstone, or milk 'of sulfur, or precipitated sulfur; or sulfur which has been acted upon by halogens previously to the action on the nickel recipitate, for instance, sulfur chlorid (SO15 the reac-' tion in the latter case being:

In the case where sulfur andnickelous hydrate and chlorin are all resent, the action is vthe same as in the case w ere sulfur chlorid is z5 'made separately and added to a nickel precipitate being treated with a halogen, ,viz., the chlorin acts upon the sulfur first forming sulfur chlorid, which immediatel decomposes in the presence of water as fol ows:

. and'these products, u on the addition of more 01 produce more S 2 from the precipitated sulfur, and l-l SO, from the H S O since H,s,o,=s+H,so,,

and the latter oxidized by 201 11,0 H 80 S01 2H01.

40 If s,o1 were used, instead of'sol as noted above, the water are 5 which, upon the addition of more chlorin,

would give SCI, and H the sulfur producing the SCI, and the other sulfur products giving the H 50 the HCl -refiiaining.

The sulfur that is precipitated by this de- 50' composition is in an extremely finely divided state, so that it is readily acted-upon by the chlorinlater. a W

In the case where sulfur chlorid is made and added to a nickel hydrate products u'pon decomposition with selplaratelg -5 5 w 'ch is eing treated with free halogen, the

In order to get this ac introduce an source, there eing continually dissolved as sary for.one atom of sulfur when sulfur is used alone. Sulfur alone, if in a finely divided state, will give a complete reaction with strong chlorin in a short time, effecting a solution of 100% of the nickel, and precipitating at no time the black nickelic hydrate; with weak chlorin much more time is required, particularly-if it is necessary to use up completely a particular batch of chlorin without replenishing the same. Sulfur chlori'd will also give 100% soluble nickel and will effect this result much more rapidly than will sulfur alone. 801 works better than 01,. WVhen S01 is utilized, only the theoretical amount need be provided in order to get complete reaction, whereas an excess of sulfur alone must be resent in order to get 100% nickel, inasmuc as its physical condition is less favorable to the reaction than is that of $01,. If any of the black nickelic hydrate is once created, it is reduced and dissolved by the sulfur in an of the forms given above when treated wit -the free halogen, V

the sulfur as a reducing agent acting as follows: The sulfur, upon being oxidized by C1,, produces HCl+ H SO which dissolves either the nickelous hydrate or the nickelic hydrate as fast as the latter tends to form, the SC) and H S O formed at the same time kee ing the solution reduced by reason of the H 0 going to S0 and the latter effecting the reduction. The excess of chlorin will not affect the solution after the nickel has been reduced and dissolved. 111 case the basic nickelous precipitate is carbonate, as NiCO .NiO,,H the reaction is recisely the same, as regards the essentials, fdr instance,

2(Nioo,.Nio,H, 6Br+ s NiSO 3NiBr, 211,0 200,.

It will be noted that the soluble nickel obtained by the above described steps is mixture of chlorids vand sulfates, and since the latter are injurious to carbon electrodes the must be removed if the solution is to be uti ized for the electrolytic deposition of metallic nickel in a cell with carbon electrodes, This can be accomplished in two Ways: (1;) by the addition ofthe proper proportionfpf CaO H when the'halogen is acting upon' the nickel precipitate in the presence of sulfur. By this means the sulfur is removed from the. solution as the nearly insoluble gypsum (CaSO and in the usual reaction one molecule of the nickelous hydrate is replaced by one molecule of the calcium hydrate, and one molecule of the nickel sulfate by one molecule of the calcium sulfate: I

mid, since the method employed does not bromid' from an outside the calcium hydrate with chlorin forms either calcium hy ochlorite or a mixture of calcium chlorid] an Ca(ClO) with a subsequent reduction of these compounds by means of sulfur to calcium chlorid. (2) By the addition of the proper amount of calcium chlorid or calcium bromid, this CaCl or CaBr, being added somewhere in the cycle with a conseuent precipitation of the sulfate as CaSO t e reaction being as follows:

the system thus continually increasing I in haloids, since halo en is being added in the form of CaCl or Ca r and there is thus dissolved continuallyin the dissolving apparatus one and one-third times as much nickel as is being plated out in the cell, which means that the system is continually increasing in nickel haloid, and some of the halogen set free in the cell would necessarily have to be used for some other purpose. or calcium sulfate which is thus formed by the above reactions is almost entirely insoluble in a normal solution, but the presence of the'metal salts renders a considerable part of it soluble, from which part the solution must be freed because, as noted above, of its damaging the anodes and also, because of its producing warty electrolytic nickel,'if the solution is supersaturated with respect to the gypsum and, consequently, a part of the latter separates out. In order to thus completely obtain an electrolyte entirely free of sulfate and suitable for electrolysis with carbon anodes, the clear nickel solution is filtered or decanted off from the agitated mixture, thereby removing the precipitated gypsum, and then the solution is evaporated until it attains a syrupy consistency, at which concentration calcium sulfate becomes entirely insoluble. The solution-of the nickel salts may be removed by filtration, decantation, orm any othersuitable manner. This degree of concentration varies with difierent solutions, but an average concentration which we have discovered is a specific gravthe production of metallic nickel and the regeneration of. free halogen, which in turn is transferred back from the cell to the dissolvingapparatus, where it, may act upon more The gypsum Y advanced to the next.

esh calaid the reaction of the sulfur, halogen and basic nickel precipitate, for instance, heat;

strong chlorin, the presence of salt in the solution whichmakes the chlorin more soluble or retains more chlorin in solution so that the reaction is facilitated, the presence of bromin even in a slight amount, having the sulfur in I afinely divided condition, and having an excess of sulfur if sulfur is used alone.

Any suitable apparatus may be utilized for carrying out our improved process. An approved form of apparatus is that shown in the drawing, to which reference has been pre-' viously made. As exemplified in such illus-c trative apparatus, we have found it convenient, in preparing a solution of nickel for electrolysis, to pump the basic precipitate around is f a tower system comprising two or more towers A in series (thus there are two shown in aforesaid figure), in order that free halogen from the cell, designated by B, shall meet in the firsttower basic precipitate or pulp nearly exhausted. The towers are preferably filled with checker-work a, as shown, whereby the descending mixture of precipitate, or pulp, is exposed over as large a surface as possible to the ascending halogen vapors. The halogen is drawn from the cell B and thence through the series of towers A by means of a suction fan A connected with the tower farthest removed from the cell, or by equivalent means. To this tower will obviously be fed the fresh supply of pulp, the sulfur andthe other necessary reagents, through a suitable feed pipe A therefor provided; and the fluid mixture as it collects in the lower portion of such first toweris raised'by means of a ump A and suitable connections a a to tie top of the tower next in order. A similar pump, not shown, serves to transfer the mixture from this tower to the next, or to the electrolytic cell, as the case may be. It will of course be understood that in practice the liquid flow is not wholly progressive, but is preferably caused to circulate a plurality of times through each tower of the series before being In the cell the nickel is being continually deposited by the current according to the equation NiBr,- Ni Br,

This free brom'in is removed from the cell, as stated, by the air blast maintained by fan A and carried to the first tower. In order to produce a good plate the conditions of concentration, temperature, and current density ing circulated in the towers becomesmore fluid as its nickel becomes dissolved, so that more pulp must be added continually, and

i-the step which consists in treating sue a prer gifiitate with free halogen in the presence of 5 fur.

2. r In a process of renderin soluble the nickel contained in basic nicke preci itates, .the step which consists in treating sue a precipitate with free halogen in the presence of finely-divided sulfur.

3. In a process of renderin soluble the nickel contained in basic nicke preci itates, the step which-consists in treating sue a pre- 2 5 6i itate with free halogen in the presence of a fur''containing body. ,4. In a process of rendering soluble the nickel contained in basic nickel preci itates, gthe step which consists in treating sue a pre- 0 f'c i 'itate with free halogen in the presence of a a1 fur-containing compound.

1. 1 5. .In a process of rendering soluble the nickel contained in basic nickel preci itates, the step which consists in treating sucli a pre- 5 ci itate withfree halogen in the presence of a 's fur haloid. 6. In a process of renderin soluble the nickel contained in basic nickefprecipitates,

the step which consists in treating such a pre- 40 ci itate with free halogen in the presenceof su fur chlorid.

7. In a process of renderim soluble the nickel contained in basic nickel preci itates, the step which consists in treating sucii a preci itate' with free bromin in the presence of s fur.

8. In a process of rendering soluble the mckel contained in basic nickel precipitates, the step which consists in treating such pre- 5o cipitate with free bromin in the presence of finely-divided sulfur. 9. In a process of rendering soluble the nickel contained in basic nickel precipitates, the step which consists in treating such a precipitate with free bromin in the presence of a sulfur-containing body.

10. In a process of rendering soluble the nickel contained in basic nickel preci itates, the step which consists in treating such a precipitate with free bromin in the presence of a sulfur-containing compound.

11. In a process of rendering soluble the nickel contained in basic nickel preci itates, the step which consists in treating sue a pre- -bromin in the presence of cipitate with free bromin in the presence of a sulfur haloid.

12. In a process of rendering soluble the nickel-contained in basic nickel preci itates,

"the step which consists in treating sue a precipitate with free bromin in the presence of sulfur chlorid. '.;.;j 7

13. In a process (if-recovering nickel from basic nickel precipitates, the steps which consist in treating such a precipitate with free halogen in the presence of a sulfur-containing bodywith the formation of nickelhaloid; and, then, electrically dissociating such haloid.

14. In a process of recovering nickel from basic nickel precipitates, the steps which consist in treating such a precipitate with free halogen in the presence of a sulfur-containing body with the formation of nickel haloid; electricallydissociating such haloid with the formation of metallic nickel and the liberation of free halogen; and, then, treating a fresh quantity of said precipitate with such liberated halogen.

15. In a process of recovering the nickel contained in basic nickel precipitates, the steps which consist in treating such a precipitate in a dissolving apparatus with free halogen in the presence of a sulfur-containing body with the formation of nickel haloid; electrically dissociating in a cell such haloid with the formation of metallic nickel and the liberation of free halogen; and transferring the latter from the cell back to the dissolving 5 apparatus.

16. In a process of recovering the nickel contained in basic nickel precipitates, the steps which consists in treating such a pre-' cipitate in a dissolving apparatus with free halo en in the presence of a sulfur haloid with the ormation of nickel haloid; electrically dissociating in a cell such haloid with the formation of-metallic nickel and the liberation of free halogen; and transferring the latter from the cell back to the dissolving apparatus,

17. In a process of recovering the nickel contained in basic nickel precipitates, the steps which consist in treating such a precipitate in a dissolving ap aratus with free fur with the formation of nickel bromid; electrically dissociating in a cellsuch bromid with the formation of metallic nickel and the liberation of free bromin; and transferring the latter from the cell back to the dissolving apparatus.

-18. In a process of rendering soluble thenickel contained in basic nickel precipitates, the step which consists in treating such a preciptate with free halogen in the presence of a sulfur-containing body and a reagent capable of precipitating the sulfate from nickel sulfate radical.

19. In a process of rendering soluble the sly-divided sulnickel c ontained in basic nickel precipitates,

the'step which consists in treating such a precipitate with free halogen in the presence of a sulfur containing body and a reagent capable of precipitating the sulfate radical from nickelsulfate as calcium sulfate.

20. In a process of rendering soluble the nickel contained in basic nickel precipitates,

ci itate with free halogen in the presence of su fur, whereby nickel haloid and sulfate are formed; and, then,- recipitating the sulfate radical from such ni kel sulfate.

23. In a process of recovering the nickel contained in basic nickel precipitates, the

- steps which consist in treating such a precipi;

tate with free halogen in the presence of sulfur, whereby. nickel haloid and sulfate are such sulfate; and, then,

formed; removin electrically dissoclating such nickel haloid.

24. In a process of recovering the nickel contained in basic nickel precipitates, the steps which consist in treating such a precipitate with free halogen inthe presence of sulfur, whereby nickel haloid and sulfate are formed; recipitating the sulfate from such nickel su ate; electrically dissociating such nickel haloid with the-formation of metallic' nickel and the liberation of the halogen; and, then, treating fresh precipitate with such liberated halogen.-

25. In a process of recovering the nickel contained in basic nickel precipitates, the step which consists in treating 'such a preci itate ina dissolving apparatus with free ha 0- gen in the presence pf a sulfur-containing body and a reagent capable of precipitating the \sulfate radical from nickel sulfate; decanting off the solution containin the nickel haloids thus formed; electrically issociating in a cell such haloids with the formation of metallic nickel and the liberation of free haloen; and transferring the latter from thecell ack to the dissolvingapparatus.

26. In a process of recovering the nickel contained in basic nickel precipitates, the

steps which consistin treating such a precipltate in a dissolving apparatus with free bromin in the presence of finely-divided sulfur and a reagent capable of precipitating the sulfate radical from nickel sulfate as calcium sulfate; decanting off the solution containing the nickel 'bromid thus formed; electrically dissociating in a cell such bromid with the formation of metallic nickel and the liberation of free bromin; and transferrin the lat,

ter from the cell back to the dissol vfirg apparatus. I

27. In a process of rendering soluble the nickel contained in basic nickel precipitates,- the steps which consist in treating sue a precipitate with free halogen in the presence of a sulfupcontaining body and a reagent cape? ble of precipitating the sulfate radical from nickel sulfate; decantin ofi'the solution containing the nickel haloid thus formed; and evaporating the same to a. consistency neces sary to precipitate the last traces of sulfate.

- 28. In a process of recovering the nickel contained in basic nickel precipitates, the

step which consists in treating such preci 1- tate in a dissolving apparatus with free ha 0- en in the presence of a sulfur-containing body and a reagent capable of precipitating the sulfate radical from nickel sulfate; decanting off the solution containing the nickel h aloids thus formed; evaporating the same tov a consistency necessary to recipitate the last traces of sulfate; electrica ly dissociating in a cell the nickel haloids with the formation of metallic nickel and the liberation of free halogens and transferring the latter from the cell back to the dissolving apparatus.

29."In a process of recovering the nickel contained in basic nickel precipitates, the steps which consist in treating such preciipir tate with free halogen in'the resence o a sulfur-containing body and a so uble calcium salt; decanting off the solution containing the nickel haloid thus formed; evaporating the same to a consistency sufficient to precipitate the last traces of sulfate; electrically dissociating in a. cell the nickel haloids with the formation of metallic nickel and the liberation of the halogens; transferring the latter 7 from the cell back to fresh basic nickel precipitate to attack the same; and adding to the solution more of the, sulfur-containing body and the soluble calcium salt.

Signed by HERBERT H. Dow and WALTER S. GATES, this 14 day of April, 1906.

HERBERT H. DOW. WALTER S. GATES.

Attested by- LE0 W. LOWE, G. L. CAMP.

Signed by ARTHUR E. ScHAEFEn, this 4 1906. ARTHUR E. SOHAEFER. Attested by- JNo. F. OBERLIN, G. W. SAYWELL.

day of April,

Correction in Letters Patent 'No. 857,927.

It is hereby certified that in Letters Patent No. 857,927, granted June 25, 1907, upon the application of Herbert Dow and Walter S. Gates, of Midland, Michigan, and Arthur E. Schaefer, of Cleveland, Ohio, for an improvement in Processes of Recovering the Nickel Contained in Basic Nickel Precipitates, an error-appears in the printed specification requiring correction, as follows: Inline 127, page 4, the word radical after the word sulfate should be stricken out and inserted after the tvord sulfate in line 126, same page; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in v the Patent Oflice. I Signed and sealed this 24th day of September, A. D., 1907.

0, c. BILLINGS,

Acting Commissioner of Patents.

[SEAL-1 

